GE side by side Model PSDS5TGXCFSS

Not maintaining temp on low side box(freezer) and medium side box(refrigerator). Control circuit from circuit board to inverter is 6VDC Amp draw on compressor is .9 Rated amps is 3.1 amps Inverter seems to be operating at low speed based on control signal This rules out inverter and compressor since there is current across compressor winding and 120V What should the control signal be? I assume it is based on set point and actual thermistor reading. If that is the case my digital reading is accurate in refrigerator+/- 1 degree. The freezer is about 10 degrees off but still should be running at full speed since set point is not close to actual reading. Would you recommend replacing the motherboard?

Once again the amp draw is .9 amps. The compressor is rated for 3.3 amps. The inverter is not running at full speed. The refrigeration system must be operating at 100% in order to properly diagnose a restriction in the system. I need to know what the control signal voltage must be at in order to get the compressor to run at full speed then at that point I can check the temperatures such as superheat and delta across the coils.

Sequence of Operation is as follows:

Example set point - 0 degees
Actual box temperature - 68 degrees

PI loop will send control signal to inverter and ramp to 100% to fully load compressor. Once box temperature is reached the PI loop will then begin to ramp down the inverter to maintain box temperature.
Does this seem correct ?

I can only assume the circuit board is faulty. Nobody can tell me what the control voltage is. If it is 12vdc I can place a 12 volt battery to test it but I cannot do this unless I am certain.
I ordered a new circuit board and thermistor. The thermistor is what controls the PI loop and then goes to the inverter.
I will update you once I replace component.